Sensim Math · Depth 한국어

2-2 · Tables and Graphs

Solve graph values step by step from clues

3.MD.B.33.OA.A.3 · take · grade 3

Archetype: Solve a Table or Graph Step by Step from Clues · step in a 5-type progression

▶ Practice — 10 problems

A class surveyed which season each student was born in and recorded the results in a picture graph. The number of students born in winter is 22 times the number born in summer. Find the total number of students surveyed.

Number of students by season of birth

The vertical axis shows the number of students from 11 to 66, one student per cell, and the horizontal axis lists the seasons (spring, summer, autumn, winter). The spring column has 66 circles, summer has 22 circles, and autumn has 55 circles; the winter column is empty.

(1) How many students were born in summer?

(2) (Number of students born in winter) =×2==\square\times2=\square students

(3) (Total students surveyed) == (spring) ++ (summer) ++ (autumn) ++ (winter) ==\square students

Number of students by season of birth 1 2 3 4 5 6 Students Season Spring Summer Autumn Winter
Show solution

Understand

A picture graph shows students by birth season: spring 6, summer 2, autumn 5, and winter blank. The number born in winter is 2 times the number born in summer. I need the total number of students surveyed.

Givens
  • Spring = 6 students, summer = 2 students, autumn = 5 students (read from the graph).
  • Winter = 2 times summer.
  • Winter's column is empty and must be worked out.
Unknowns
  • The number of students born in winter.
  • The total number of students surveyed.
Constraints
  • Each circle stands for 1 student.
  • The total is the sum of all four seasons.

Plan

#7 Identify Subproblems · also uses: #1 Draw a Diagram

Solve the knowable pieces in order: read summer, use the doubling rule to get winter, then add all four seasons for the total. Reading circle counts off the graph supports each step.

Execute

#1 Draw a Diagram 3.MD.B.3
The summer column has 2 circles, so 2 students were born in summer.
Counting a column's circles is direct picture-graph reading.
#7 Identify Subproblems 3.OA.A.3
Winter is 2 times summer: 2 × 2 = 4 students born in winter.
2×2=42 \times 2 = 4
'2 times' means double the summer count — a Grade 3 multiplication idea.
#7 Identify Subproblems 3.MD.B.3
Total = spring + summer + autumn + winter = 6 + 2 + 5 + 4 = 17 students.
6+2+5+4=176 + 2 + 5 + 4 = 17
The whole survey is just the sum of every season's count.
Answer: 17 students

Review

All season counts are small whole numbers (6, 2, 5, 4) and their sum 17 is a believable class size; winter (4) is indeed double summer (2), matching the rule.

Add the three known seasons first (6 + 2 + 5 = 13), then add winter (4) to get 13 + 4 = 17 — same total.

Standards · min grade 3

  • 3.MD.B.3 Draw and interpret scaled picture graphs and bar graphs — Reading season counts from the picture graph and summing them for the total.
  • 3.OA.A.3 Solve multiplication and division word problems within 100 — Doubling the summer count to find the winter count.
💡 This only needs Grade 3 'double it' multiplying and adding the columns — solve the knowable parts first!